| A | B |
|---|
| The universe is organized according to a | loosly arranged structure |
| The three major types of galaxies identified by Edwin Hubble are | spiral elliptical and irregular |
| Why do scientists study distant galaxies to learn about early galaxies | it takes a long time for light ot travel through space so looking at distant galaxies shows what early galaxies looked like |
| A white dwarf is a type of star that has | used up all of its hydrogen and is the leftover center of an older star |
| Absolute magnitue refers to | the brightness of a star at a distance of 32.6 light years form Earth |
| A black hole | is an object so massive and dense that not even light can escape its gravitational pull |
| Main sequence | is the diagonal pattern on the H R diagram where most stars appear |
| Apparent magnitude | is the brightness of a star as seen from Earth |
| Quasar | is a distant star like source of light |
| light year | the distance that light travels through in one year |
| light year | about 9.5 million kilometers |
| cosmology | the study of origin structure and future of teh universe |
